CMake: check compiler flags are supported before adding them

Signed-off-by: Steve Lhomme <robux4@ycbcr.xyz>

Author: robUx4

CMakeLists.txt

@@ -104,6 +104,8 @@ set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_C_EXTENSIONS OFF)
 
+include(CheckCCompilerFlag)
+
 # Set compiler flags and options.
 if(MSVC)
   message("Not supported yet!")
@@ -121,8 +123,27 @@ elseif(UNIX OR MINGW)
         set(OPT_DBG "-DNDEBUG") # disable assert
     endif()
 
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OPT_DBG} -${OPT_LV} -fomit-frame-pointer")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wno-unused-function -Wno-pointer-sign -Wno-pointer-to-int-cast")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OPT_DBG} -${OPT_LV}")
+    check_c_compiler_flag("-fomit-frame-pointer" HAS_FLAG_OMIT_FRAME_POINTER)
+    if(HAS_FLAG_OMIT_FRAME_POINTER)
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")
+    endif()
+    check_c_compiler_flag("-Wall" HAS_FLAG_WARNING_ALL)
+    if(HAS_FLAG_WARNING_ALL)
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
+    endif()
+    check_c_compiler_flag("-Wno-unused-function" HAS_FLAG_NO_UNUSED_FUNCTION)
+    if(HAS_FLAG_NO_UNUSED_FUNCTION)
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-function")
+    endif()
+    check_c_compiler_flag("-Wno-pointer-sign" HAS_FLAG_NO_POINTER_SIGN)
+    if(HAS_FLAG_NO_POINTER_SIGN)
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-pointer-sign")
+    endif()
+    check_c_compiler_flag("-Wno-pointer-to-int-cast" HAS_FLAG_NO_POINTER_INT_CAST)
+    if(HAS_FLAG_NO_POINTER_INT_CAST)
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-pointer-to-int-cast")
+    endif()
     if(NOT WIN32)
       set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
     endif()

src/CMakeLists.txt

@@ -14,6 +14,10 @@ file(GLOB LIB_AVX_INC "../src/avx/oapv_*.h" )
 include(GenerateExportHeader)
 include_directories("${CMAKE_BINARY_DIR}/include")
 
+include(CheckCCompilerFlag)
+check_c_compiler_flag("-flax-vector-conversions" HAS_ARM_VECTOR_CONVERSION)
+check_c_compiler_flag("-msse4.1" HAS_SSE41)
+check_c_compiler_flag("-mavx2" HAS_AVX2)
 
 message("SYSTEM_PROCESSOR=${CMAKE_SYSTEM_PROCESSOR}")
 
@@ -107,10 +111,16 @@ if(MSVC)
   endif()
 elseif(UNIX OR MINGW)
   if (ARM)
-    set_property(SOURCE ${NEON} APPEND PROPERTY COMPILE_FLAGS "-flax-vector-conversions")
-elseif (X86 OR UNIVERSAL)
-    set_property(SOURCE ${SSE} APPEND PROPERTY COMPILE_FLAGS "-msse4.1")
-    set_property(SOURCE ${AVX} APPEND PROPERTY COMPILE_FLAGS " -mavx2")
+    if(HAS_ARM_VECTOR_CONVERSION)
+      set_property(SOURCE ${NEON} APPEND PROPERTY COMPILE_FLAGS "-flax-vector-conversions")
+    endif()
+  elseif (X86 OR UNIVERSAL)
+    if(HAS_SSE41)
+      set_property(SOURCE ${SSE} APPEND PROPERTY COMPILE_FLAGS "-msse4.1")
+    endif()
+    if(HAS_AVX2)
+      set_property(SOURCE ${AVX} APPEND PROPERTY COMPILE_FLAGS "-mavx2")
+    endif()
   endif()
 
   if(OAPV_BUILD_SHARED_LIB)